


Tale of under ocean

by KotoriYui



Category: Shingeki no Kyojin | Attack on Titan
Genre: AU, Falling In Love, Fantasy, Humor, M/M, Merman!Eren, Moody Levi, Other Additional Tags to Be Added, Pirate!Levi, Pirates, Requested fic, Romance, ereri, mermaids/mermen, naive Eren
Language: English
Status: In-Progress
Published: 2016-04-15
Updated: 2016-06-07
Packaged: 2018-06-02 08:14:51
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,496
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6558979
Author URL: https://archiveofourown.org/users/KotoriYui/pseuds/KotoriYui
Summary: <blockquote class="userstuff">
              <p>Eren has a special and unique power, however he cannot talk about it with anyone. So he decides to explore his power as much as he can. Yet he had never expected to find that special feeling so suddenly and much less in a gorgeous yet arrogant man. Two different people from two different worlds, what kind of relationship will be born between both of them?</p>
            </blockquote>





	1. Chapter 1

**Notes for the Chapter:**

> Yô -0-)/  
> This was requested by a friend (she has an ao3 acc, I think lol, but I have no idea what her name is lmao thus I'm gonna tag her ff acc instead), [bby](https://www.fanfiction.net/u/2746484/Black-Cat-of-the-Black-Rukh/) (if you ever enter here let me know xD). She saw the cover of the dj "Tale of under ocean" and only God knows why xD, she asked me to write something based on that cover with the same title x) I thought "well, why not?" but 2 years have passed and I have yet to continue and finish this fic lmao. I couldn't have done it before because I wasn't in the right mood ~~ but now, finally, I feel like doing it :'D so I decided to post it here as well. (also written on my [ff acc](https://www.fanfiction.net/u/4797506/Kotori-Yui/) )  
> Rating will surely go up, bc one of my friend's requirements was smut xP~  
> Also think of Levi as a bottom, bc to me he was made to be loved -w- ❤  
> IMPORTANT WARNING: My native language is not Eng, thus beware of ugly mistakes!! I apologize in advance for them. I've re~read this and corrected it but I know that there are remaining mistakes haha. Just tell me if you read something really bad and incoherent, just don't be rude pls ;u; thank you ~

Azure Kingdom, a pacific kingdom under the ocean inhabited by beautiful and legendary creatures known as mermaids. Between all those mermaids was Eren Jaeger, a merman who had strange and unique powers; he could turn into a human boy only by biting the skin over his thumb. The first time he had found out that he had such a power inside of him, he had been completely astonished and afraid. Why and how could he turn into a human? He didn't remember about anyone else of his family having such powers; so he assumed that that wasn't genetic. He tried to remember about any other mermaids of the whole kingdom, his friends, and even the royal family but no one could turn into a human being. The more he tried to understand his power the more afraid he would become. He even thought about telling this to someone but what if they tried something against him? Mermaids were known by their hatred against humans so they could try to kill him in worst case scenario. However Eren didn't think about humans as bad people because of his best friend Armin a cute little merman who loved the unknown and was always telling Eren fantastic stories about the human world that he read in old books. Eren had begun to develop a strange curiosity about humans and their world, so he decided to keep that secret only to himself and try to find out the unknown of that fantastic world on his own.

The first time he had tried out his powers, after being aware of them, he had been able to turn into a human being for only a few seconds. His whole core had trembled until the last scale of his beautiful blue green fin, and his heart had beaten so fast that he thought he would die. Nevertheless he suddenly began to doubt of his own powers, yet he had remembered the strange sensation of having two legs instead of his fin and he quickly stopped doubting. He had felt so free, so incredible that he wanted to feel in such a way again. That day he tried his power over and over again, and the last time he tried it he was able to stay as a human for 5 minutes. He even had to swim to the surface to breathe properly, since he had lost his mermaid senses.

The following days Eren just kept trying to control his powers. He bit his thumb countless times, and in each bite the time he could stay as a human being increased. After so much practicing Eren was finally able to control his strange powers; the time he could stay as a human being was now of 2 whole hours. Thus, and without even knowing it, thanks to his strange power, he would be able to find out love.

 

* * *

 

 _"Great, today for the first time I'll know the human world!"_ Eren thought feeling excited already. He swam to the surface and took a deep breath smiling from ear to ear. _"Ah, this is totally different from the sea…”_ Just by feeling the fresh air of the human world, provided him a great feeling of satisfaction and pure bliss. He felt such freedom that he was starting to love the human world too much already. _“Okay Eren, stop daydreaming and go_ _actually_ _explore!"_ The brunet swam to the seaside and once he tried to get up on his feet, he fell flat on the golden sand. He frowned in confusion and tried to get up one more time, but just like before he simply fell down. He didn't give up nonetheless. He persisted over and over again on getting up and walking but the result was always the same.

 _"I… I can't walk."_ He concluded in shock. Eren was confused; afraid; astonished. Why couldn't he walk? What would he do now? For the two next hours he couldn't return to his normal self; although he did know how to control his powers and be able to stay as a human, he didn't know how to reverse the transformation, thus he would have to inevitably wait. _"But I can't wait here, I'm completely naked!_ _For what Armin told me, humans wear clothes-_ _AAH! What will I do now?"_ Eren bemoaned his unfortunate situation feeling desperate and a little sad, _"Why couldn't I think about this before? Of course I can't walk; I never walked in my whole life so it's normal that I don't know how to do it. And I finally can control my power but I can't walk out there and explore this world. I feel so stupid. I wish I could be a complete human being."_ Eren closed his eyes softly, already giving up, when suddenly an intense deep voice sounded in his ears, bringing him back to reality.

"Hey you…?" The voice said forcing Eren to look up at the one who was talking. Upon focusing his blue green orbs on such a gorgeous and handsome male, Eren lost the ability to think and breathe. The deep grey eyes looking back at him made his heart race like crazy against his ribcage. The merman was totally, utterly enchanted and fascinated by the human.

"Y-Y-Yes?" Eren stuttered innocently; clumsily, taken aback and lightly flushed due to the other man's attractiveness. He had never seen such a perfect creature in his whole life; and his kingdom was full of beautiful and unique creatures.

"You're in my way, get out." The handsome man said so arrogantly and coldly that it made the brunet shiver in shock.

Eren frowned, clearly not expecting to hear nor see such an harsh tone of voice and attitude from the perfect human. It took him some time to register what had just happened, yet when he did so, an expected irritation started to boil within him. _"_ _What the hell’s up with this man?!_ _"_ Eren couldn't understand how such a charming human could be so cold and harsh towards someone he had just met. Couldn't the man see that he was not okay? No; couldn't the man see that he was completely naked?

" _I-It's true Eren, you're naked! They will think_ _that_ _you're a pervert!"_ Eren blushed deeply looking away. He didn't dare to face the fascinating human in such a… abnormal situation. It was unbelievable… the first time he had come to the human world to explore, to know the unknown; something like this had to happen. Why couldn't things end up the way he wanted, for once?

"Né you; are you alright? Do you need help?" A different tone of voice asked, still Eren didn't look up. He simply remained in the same position in order not to embarrass himself even more.

"Oi Erwin…!" The gorgeous male, Eren recognized, shouted in irritation which made the merman feel even more down and ashamed.

"He can be hurt Levi. Besides he's naked, probably someone stole his clothes." The other man said, and gently bent down with an extended hand towards the brunet. The man, Erwin, asked softly one more time, "Do you want to come with us?"

**Notes for the Chapter:**

> I know, pretty short right? But I can assure you that next chapters will be way longer x)  
> I hope it hadn't been a bad read so far x] ~  
> Gimme a month and half, and I'll update again ;3 (yes, this long because I have more stuff to update TuT)  
> Jaa, bye~bye ❤⌒ヽ(*'､^*)chuu*~


	2. Chapter 2

**Notes for the Chapter:**

> Yô -0-)/  
> waah I'm sorry, this took me a bit longer than a month and half to update but I suddenly got two people requesting me fics and I decided to get done with that (although in the end I am not done with that yet lmao I'm almost though xD)  
> Anyways, thanks for all the kudos and comments so far *3* I hope to not disappoint you, let's see... xP haha  
> Then pls go enjoy the chapter *mistakes ahead, be careful with your eyes while reading*

"Eren, where have you been?" The blond merman asked clearly concerned and lightly panicked, Eren noticed. The brunet felt instantly guilty. He hated to see Armin so worried with him, although he knew that that was something inevitable since they had practically grown up together. It all had started when they were much younger, a group of 3 rebel mermen had attacked Armin due to the blond's great curiosity and interest in the human world. Mermaids were known by their hatred towards humans due to the cruel way they had treated them in the past, when both kinds still coexisted together. Of course, not all the humans had tortured the legendary creatures, however all of them had been labeled in the same way. It was typical, though unfair as well, either for humans and mermaids. Therefore, obviously, those who showed the slightest interest in the world above the ocean, would be judged; bullied; and in the worst case, when confronted by a mermaid with greater hatred, the innocent curious creatures would even be killed; like Armin’s parents had been. Fortunately the three idiots who had attacked Armin in the past, were just the bully type and simply liked to beat the crap out of the weakest ones, plus laugh their asses off at their idiotic actions. Eren had been so fed up with that kind of people, that when he had realized, the three bullies had been beaten up by him and had ran away right after, cursing the brunet. After that Armin had gotten closer to Eren and vice versa. They had clearly established a connection and before they knew it, Eren and Armin were very attached to each other; inseparable. 

It was precisely because of sharing such a deep bond with Armin that Eren felt so guilty for having to hide his most important secret from his best friend. It was not that he did not trust the blond, it was just that he did not want to involve him in unnecessary danger. Thus, Eren's only choice was lying. 

"I went to one of the caverns I found exploring. Why? Did something happen while I was out?" Eren asked trying to seem natural. But, of course, Armin wouldn't be easily fooled. 

"Hum-" The blond merman got closer to the brunet, their faces mere inches away from each other's. Armin observed Eren carefully, studying his now nervous expression; the way his forehead sweated lightly; the way his eyes avoided Armin's every now and then not too discreetly; the way his Adam's apple bobbed up and down while Eren swallowed thickly in anxiety... Armin made sure to observe every single detail intensely. 

"W-What?" Eren stuttered nervously. 

"You're lying." 

Ah; Eren should have really known that there was no point in trying to hide things from Armin, as the blond would always see through him. However, it didn't matter if he knew the truth or not, Eren wouldn't involve Armin in this. 

 

* * *

 

Levi was irritated. He was soaked to the bone, his favorite jacket was dirty, besides being completely soaked too, and the rest of his clothes in general were a total mess. And it had all been that insolent bastard’s fault. If Levi ever saw him again… No, he better not, if he did he would kill him for sure. 

“Whoa Levi, what happened? Why are you looking like that?” Erwin inquired clearly surprised. The blond man was sitting at the desk of his private small office, reading and signing paper after paper as if there was no tomorrow. Levi instantly assumed that those papers were related to their next trip. Would they be leaving soon? Levi really hoped so. He had disliked this small town ever since he set foot in it two days ago, and after the occurrences with the other bastard, Levi found himself disliking that place even more. 

But, at the moment he couldn’t care less about that. Levi was too upset to even think of other things. He scowled at Erwin, inwardly blaming him as well for his disgraceful appearance. The older man was the one at fault too for that, after all he had been the one asking him to take care of the other brat after they had gotten to their ship. If not for Erwin, Levi’s clothes would still be perfectly proper to dress.  

“You will get some nice wrinkles if you keep scowling that much so often, Levi.” Erwin stated ironically, with a very small grin in his lips. 

“Like I care. And if I ever get them it’ll be your fault too for forcing me to babysit unknown brats.” Levi replied right away, more annoyed due to the blond's statement. Sometimes he felt like Erwin mocked him on purpose just with the intention of seeing him in this state of irritation. Did the man had pleasure in seeing him like this? Tsk, if he didn't respect the blond so much, he would kill him surely. 

"Oh, so you helped Eren to get home after all." The man paused briefly to hum in appreciation at Levi's good gesture; though he had been the one requesting him to do it. "How was it? Could he walk better by the time he got there? But, what an unlucky boy he is... Being robbed like that in the middle of the day, plus beaten up to the point of getting unable to walk. This world is full of mean people." The blond narrowed his eyes deep in thought. He had realized that long ago, and although he would like to change the way people thought and chose to live, Erwin knew that changing their minds wasn't an easy task.  

"Walk...? If he could walk, you ask... Of course he couldn't walk! Why would I get back all drenched like this if he could walk like a normal person?" Levi's scowl deepened as he recalled how Eren had stumbled and made them  fall inside of a damn fountain; Levi fell on his back with the brunet sprawled all over him.  

"I see. How unfortunate. I hope he recovers soon." 

"Tsk" He seriously couldn't take it anymore. "I'll be in my cabin." Levi said turning around on his heels, more than ready to leave, but before doing so the older man added. 

"We'll be leaving in two weeks." 

"Perfect." As if! Two weeks stuck in that small and poor town was too damn long. He really wished to leave tomorrow. A lot of the people in that place reminded him of his awful past, when he lived in the streets as if he was garbage, without a single thing to eat or to drink. If not for Erwin, he would for sure be living like that yet. Levi suddenly felt more irritated with his bitter memories. Why couldn't he forget about his past for once and for all? "Shit" He muttered in a small voice. That place wasn't bringing him anything good so far; and he utterly doubted it ever would. 

"Have you said something?" Erwin asked. 

"No." Levi replied, finally leaving the small office. He needed a fucking bath and some rest to get rid of his irritation and the frustration.   

 

* * *

  

“Eren, where are you going?” Mikasa inquired following her brother closely. As usual the beautiful mermaid would follow the brunet around anywhere he went. Eren barely had space to breathe. He knew that Mikasa didn’t mean bad since she was just being overprotective of him, but Eren just needed his time alone at times, to think things over. Yet Mikasa didn’t seem willing to let that happen. Eren knew that she was most likely concerned over him and the fact that his blood would usually boil up in rage very easily at the smallest of things. But damn, this time that wouldn’t be the case; in the slightest. Far from that. Eren had a simple thought and destination in mind, however with Mikasa glued to him like this would be hard for him to go anywhere he wished. 

“I’m just going to explore some caverns near the castle. You can return.” Eren knew that his words wouldn’t work that easily on Mikasa. 

“Then I’m going with you.” 

Of course she would say that. 

He sighed, reluctantly saying, “Sure.” What else could have he said anyways? 

 

* * *

 

Now it was his opportunity. If he wanted to escape, then he should do it while Mikasa was distracted with the cavern they had been exploring for the past hour. Eren knew that he would be a jerk for doing this, but he would certainly apologize to his sister later.  

The brunet swam away from the cavern, the castle right next to it, and soon enough he was greatly distant from it, but especially from Mikasa. Now he could bite his finger and turn into human, so he could go visit the town above, Erwin and the people who had helped him yesterday, and… 

 _“Levi-“_  

His heart raced as he uttered the other man’s name. He had no idea why that arrogant human provoked such reactions in him, but before he could even notice it, his mind would be sending him short flashbacks of the gorgeous and handsome features of the man and his heart would thump like crazy inside his chest.  

Perhaps it was because he was a human… But Erwin and the other people inside the blond’s ship didn’t cause such reactions within him… Well, either way he would think about that later, now he just wanted to go to the world above and see Levi to thank him for yesterday- 

“AAAH!” The brunet suddenly shouted as he recalled all the events from the previous day. He paled considerably when a flashback of Levi’s scary scowl attacked his brain all of a sudden. He could also still remember his deep and menacing tone of voice as if the man was talking to him right now, right here. Eren’s heart raced yet again, but now in a mixture of shock, fear and anxiety. Eren knew that the man had gotten furious with him because of their fall, but it hadn’t been on purpose. Eren couldn’t still walk too well, so the event from yesterday had been an unfortunate mistake. However he was almost sure that Levi didn’t share the same opinion as him. The man also appeared to be a bit stubborn. The brunet sighed in frustration. What should he do now? Well, apologizing was certainly the right thing to do, but how should he do it? Levi was a human; did humans apologize in the same way as mermaids?  

Suddenly an idea popped up in his head. A couple of months ago Armin had borrowed him some books and in the major part of them, people apologized always in a certain way. So, what if he did the same? Whoever received the apology had always seemed very pleased with the gesture, so maybe Levi would appreciate it too. Suddenly Eren found himself beaming at his idea. The anxiety and fear he felt before abandoned his body in no time. Great. Now he just had to go get _that_ and then he could finally go see Levi.  

Eren was now anxious for different reasons. 

 

* * *

 

A soft knock on the door of his cabin was enough to awake him which left him moody with good reasons for it. Levi hated; he really hated to be awoken no matter what the reasons could be. But, he especially hated it if he was sleeping cozily and comfortably, which was something rare as he usually would have nightmares and be unable to sleep properly for the rest of the night. But, all that aside, Levi had decided to ignore the knock on the door and pretend that nothing had awaken him, so no one would get to see a moody Levi in the morning.  

Yet, another knock, this time a bit more frantically, made it impossible to ignore. 

Levi scowled, yet again, and got up from his comfortable bed, heading to the door of the cabin and opening it abruptly which, he was sure, would scare the shit out of whoever had dared to leave him in this state of moodiness so early in the morning. His grey orbs had checked his wrist watch placed near his pillow.  

Once the door was fully opened, Levi’s eyes widened incredibly with the sight of that annoying brat from the previous day. For brief moments he remained quiet, controlled by surprise, yet when he thought that he could finally react and demand the fucking bastard some explanations for his unexpected appearance, the brunet astonished him to the point of leaving him speechless and motionless.  

Eren kneeled down in front of him, grabbing one of his hands as he did so, and extending towards his shocked self a flower of different shades of blue.  

“Levi, I apologize for yesterday’s events.” Eren said sincerely, though he was nervous as hell. Had he said and done this well? He thought so, as he recalled the last book he had read. However Levi’s expression didn’t allow him to know if the man had appreciated the gesture or not. Argh, why did Levi have to be so hard to read? 

Eren’s blue-green eyes observed the other man carefully. Levi’s mouth was opened in an ‘o’, his eyes were comically widened… Levi was clearly taken aback. Still, Eren hoped he could accept his apology. Ah he was suddenly nervous. Why wasn’t the man reacting any differently already? 

As if reading his mind, Levi finally spoke, “Oi brat,” His voice sounded low, deep and serious. “…do you have a death wish?”  

Eren’s heart skipped a beat at that question. And it was then that Eren realized that his gesture hadn’t been appreciated, and that his apology hadn’t been accepted. What would it be of him now?

**Notes for the Chapter:**

> What kind of books have you been reading Eren bby? OvO)? hahaha x3  
> Well I have to confess that the part I enjoyed writing the most was the last one x3 kawaii naïve merman!Eren -3- 
> 
> Then, I hope to see you on next chap too :3  
> Bye~Bye, ❤⌒ヽ(*'ε^*)chuu*


End file.
